Re: [PATCH] ALSA: usb-audio: Disable USB autosuspend properly in setup_disable_autosuspend()

[Kai-Heng Feng]

Hi Joakim,

On Thu, Mar 4, 2021 at 5:50 PM Joakim Tjernlund
<Joakim.Tjernlund@xxxxxxxxxxxx> wrote:
>
> On Thu, 2021-03-04 at 12:34 +0800, Kai-Heng Feng wrote:
> > Rear audio on Lenovo ThinkStation P620 stops working after commit
> > 1965c4364bdd ("ALSA: usb-audio: Disable autosuspend for Lenovo
> > ThinkStation P620"):
> > [    6.013526] usbcore: registered new interface driver snd-usb-audio
> > [    6.023064] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x0, type = 1
> > [    6.023083] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x202, wIndex = 0x0, type = 4
> > [    6.023090] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x0, type = 1
> > [    6.023098] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x202, wIndex = 0x0, type = 4
> > [    6.023103] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x0, type = 1
> > [    6.023110] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x202, wIndex = 0x0, type = 4
> > [    6.045846] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x0, type = 1
> > [    6.045866] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x202, wIndex = 0x0, type = 4
> > [    6.045877] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x0, type = 1
> > [    6.045886] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x202, wIndex = 0x0, type = 4
> > [    6.045894] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x0, type = 1
> > [    6.045908] usb 3-6: cannot get ctl value: req = 0x81, wValue = 0x202, wIndex = 0x0, type = 4
> >
> > I overlooked the issue because when I was working on the said commit,
> > only the front audio is tested. Apology for that.
> >
> > Changing supports_autosuspend in driver is too late for disabling
> > autosuspend, because it was already used by USB probe routine, so it can
> > break the balance on the following code that depends on
> > supports_autosuspend.
> >
> > Fix it by using usb_disable_autosuspend() helper, and balance the
> > suspend count in disconnect callback.
> >
> > Fixes: 1965c4364bdd ("ALSA: usb-audio: Disable autosuspend for Lenovo ThinkStation P620")
> > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
>
> I got an report from a co-worker who has no USB sound from a Lenovo ThinkPad in a Ultra Dock.
> USB HS is connected to Dock USB jack.
> Could this be the same problem?

It's a different issue. Please file a separate bug report.

Kai-Heng

>
>  Jocke